Known touchless dispensers of hand cleaning fluids are triggered by sensors which measure relative changes of environmental conditions such as in the case of known infrared sensors, optical reflectants and, in the case of capacitive sensors, the change of a capacitive field around the sensors. Such known sensors typically measure a relative change of the environmental conditions within a certain time frame. Such known infrared sensors and capacitive sensors suffer a number of disadvantages. For example, infrared sensors are often rendered inoperative due to infrared radiation which may arise and change in the environment. Capacitive sensors may have difficulty measuring the change in capacitive fields depending upon the environmental conditions.
Some known touchless dispensers provide for a number of different sensors to control different features. For example, one infrared sensor may determine the presence of a user's hand below a fluid outlet and another infrared sensor may be provided on the dispenser at a different location as to sense hand gestures as delivered by movement of a user's second hand above the dispenser, for example, to dispense an additional dosage of liquid.
Currently known dispenser systems do not provide a simple arrangement of a sensor for both triggering liquid dispensing and provide an input for hand movement controlled gestures.
The inventors of the present invention have appreciated that known sensors for paper towel dispensers and toilet paper dispensers merely determine the signal condition such as, for example, an empty condition and do not provide other information useful for the control and management of the dispenser. Similarly, sensors used to sense the level of waste within a waste bin typically provide input on but a single condition such as, for example, a full condition and suffer the disadvantage they do not provide other information by a single sensor which can be useful in the control and management of waste bins.